1. Sift the flour, baking soda, cornstarch, salt, into the bowl of dough. Mix well.
2. In another container, mix the melted butter, granulated sugar and brown sugar,stirring until the sugar dissolves and blends in with the butter. Dough into dough-like caramel. Enter the egg intact and egg yolks, mix well. Stir in vanilla paste, stir well.
3. Pour the wet dough into the dry dough, mix well with a wooden spoon. Stir in chocolate chips, mix well.
4. Cover the bowl with plastic wrap, chill the dough in the refrigerator at least 3 hours.
5. Remove the dough from the refrigerator, allow 10 minutes for easy set up. Shape the dough with your hands to form a circle is not perfect of ping pong balls, or depend on your desire.
6. Prepare baking paper on baking sheet, give the distance between the dough.
7. Take a little bit of dough with fingers. There is no need to make a perfect surface. Give some extra chocolate chips on the surface of cookies, press half goes into the dough.
8. Bake in an oven heated to 180 degrees Celsius over the next 11 minutes.
9. Remove from oven, let cool 10 minutes, transfer the cookies to the top shelf, let it cool completely. Store in a sealed container.